DE.U.9402633 discloses a nozzle device of said kind, in the form of a machined assembly which uses two threaded fasteners to clamp a planar abutment surface of a cover plate part onto an abutment surface of a nozzle body part so as to cover one side of a hollow formation providing a nozzle, a feed passage and an inlet duct recess, in the hollow body. For cleaning of the abutment surfaces, the assembly has to be disassembled, i.e. both fasteners need to be removed and the cover plate part lifted off the body in order to move its planar abutment surface directly away from the abutment surface on the body part. One of the fasteners extends through a cut-out in the cover part so that when the fasteners are partially released the cover part can be pivotally moved about the axis of the other fastener. However, even when the nozzle opening is exposed by such pivotal movement, portions of the abutment surfaces remain in abutment and cannot be wiped clean.
WO a 95 07 580 disclosed a two-part plastics injection moulding which is not of said kind and is primarily directed to the provision of a very smooth curved path or feed passage between an inlet and a nozzle outlet so as to reduce the tendency of materials to accumulate along the feed path in a moulded plastic nozzle device for an aerosol spray can. In most embodiments a two part body is used to hold in place a flexible tube which integrally includes the inlet, feed passage and nozzle opening, whereas in the embodiment shown in FIG. 14 the tube is omitted and the feed passage is defined between the two parts of the body, and these two parts are permanently connected together by an integral hinge, and together provide sockets for an inlet member and a separate nozzle member which respectively define the inlet and the nozzle opening. However, in no embodiment can the nozzle opening be wiped clean if it blocks so that the problem of nozzle blockage and effective sealing of the interface between said parts in the FIG. 14 embodiment remain.
From GB 2161401A there is known a cream dispenser having a nozzle device in which the second part is hollow and defines a passage leading from the nozzle opening at one end to another opening at the other end. Said other end is connected by a hinge to the first part so that the second part can be swung away from the first part to provide access to both said ends for rinsing out the passage in the second part. However, if the passage becomes blocked, rinsing is prevented and resort must be made to poking out the blocking material with an implement inserted via one or other of the openings.
Where finer nozzle openings are concerned for producing "atomized" sprays, the use of even a very fine implement to unblock the nozzle opening may not be practical or expedient, and may lead to damage to the -nozzle to the detriment of the spray pattern.
These problems are tacked by U.S. 3961756A which discloses a nozzle device in which the first part is formed to provide both the inlet and the nozzle opening, and the second part is in the form of a threaded valve plug which is rotatable in a threaded socket in the first part to move axially relative to the internal side of the nozzle opening to vary the spray pattern. The plug is removable to provide access to the inside side of the nozzle opening for removal of matter blocking the inside side of the opening.
However, the problems of blockage of the nozzle opening itself and the removal of residues sticking to the internal surfaces of the nozzle remain.